I don't want to see this discussion go down the road of "Did Ueshiba train with Chinese stylists and get his aiki from them," because I believe strongly that that's the wrong direction. Instead, the focus should be on "where did aiki and internal training methodology come from?" That's where the "Chinese connection" comes in, and it enters long before Morihei Ueshiba or even his teacher, Tokaku Takeda.

Ueshiba's aiki came from Sokaku Takeda, via his Daito-ryu vehicle. Where did Takeda get it...? Ellis Amdur toys with the possibilities in "Hidden in Plain Sight," but the mists of time and lack of recorded history obfuscate any tangible proof. Instead, we are left with the young Takeda's mysterious learning experience with the Shinto scholar, Tanamo Saigo (AKA Hoshino Genshin) who, as with other high-born Japanese scholars of the day, was well versed in Chinese classical literature, ranging from Taoist texts to Confucian and possibly other estorica that may or may not have included certain esoteric internal exercises (qigong, neigong) the Chinese got, in ancient days, from Indian Buddhist and Tantric monks.

There's not much point to arguing the very genuine connection between Japanese "aiki" and internal body method, and that of its Chinese counterpart. It is what it is. Japan is famous for taking an idea and running with it -- look what the Japanese did with cameras and automobiles -- and integrating it into its culture. I believe that a relatively small number of Japanese, probably clan heads and others with connections on a higher level to Chinese teachers, herbalists and medical practitioners, nobles and religious figures, had a fertile cultural exchange and received this special knowledge. Then they proceeded to study it, dissect it, adapt it to suit their needs within their family/clan martial systems or other private institutions. The knowledge, in Japan, perhaps became proprietary as a result, and that would explain why it's such a "novel concept" to all but another relative few folks today.

That said, there are plenty of proofs on a contemporary note, of the Chinese-Japanese aiki/IP connection. The Chen tai chi master Liu Cheng-De, who is noted for his internal power, is quite well known to have lived in Japan for 10 years, during which time he taught aiki to a couple of Sagawa's disgruntled Daito-ryu students who felt they weren't "gettin' any of it" from Sagawa. It's quite certain, then, that they recognized Liu's skills as being what Sagawa had (and, by context, what Ueshiba had, what Sokaku Takeda had), even though Liu was Chinese, and had come with only his Chinese martial upbringing.

Even more contemporarily, there are people on these Internet pages, myself included, who have trained both in Daito-ryu aiki/IP and in their Chinese equivalent, in my case I Liq Chuan. I can state quite frankly that they are... the same animal. The way they are expressed physically and martially is different (there are myriad ways you can manipulate and apply aiki), and the training exercises for their development show superficial creative differences, but the root body conditioning and method are virtually identical. The aiki and the power are identical. I know for a fact that I Liq Chuan's internal method is purely a product of its Chinese heritage.

And while there of course is such thing as simultaneous and synchronous invention of things in different places, such as the printing press and, possibly, the wheel, something as complex, nuanced and sophisticated as an internal body method is very, very unlikely to be something that two different peoples could event, identically, without any cross-pollination of ideas. Add to that the fact that China did exert great cultural influence on Japan and much of Asia, and that the two nations were neighbors separated only by water that was navigable by ship, and it even further decreases any possibility that aiki/IP could be uniquely Japanese, with China and its powerful internal method right next door.